Express your answer as a mixed number simplified to lowest terms. $20\dfrac{2}{6}-6\dfrac{3}{8} = {?}$
Simplify each fraction. $= {20\dfrac{1}{3}} - {6\dfrac{3}{8}}$ Find a common denominator for the fractions: $= {20\dfrac{8}{24}}-{6\dfrac{9}{24}}$ Convert ${20\dfrac{8}{24}}$ to ${19 + \dfrac{24}{24} + \dfrac{8}{24}}$ So the problem becomes: ${19\dfrac{32}{24}}-{6\dfrac{9}{24}}$ Separate the whole numbers from the fractional parts: $= {19} + {\dfrac{32}{24}} - {6} - {\dfrac{9}{24}}$ Bring the whole numbers together and the fractions together: $= {19} - {6} + {\dfrac{32}{24}} - {\dfrac{9}{24}}$ Subtract the whole numbers: $=13 + {\dfrac{32}{24}} - {\dfrac{9}{24}}$ Subtract the fractions: $= 13+\dfrac{23}{24}$ Combine the whole and fractional parts into a mixed number: $= 13\dfrac{23}{24}$